Evaluation of the Bio-efficacy of Granular Insecticides in Managing Paddy Pest Infestations

Abstract

Effective pest management in rice is crucial for maintaining crop productivity and reducing economic losses in agriculture. This study aimed to evaluate the efficacy of various insecticides and their combinations against major rice pests during the Kharif seasons of 2021, 2022, 2023, and Rabi 2023-24 at the Agricultural Research Station in Ragolu, North Coastal Zone, Andhra Pradesh. A total of 14 treatment strategies were tested, incorporating different combinations of insecticides. These included seed treatments with T1 - Thiamethoxam 25% WG, T2 - Carbofuran 3% CG, T3 - Fipronil 0.3 GR, T4 - Chlorantraniliprole 0.4 GR, T5 - Carbofuran 3% CG, T6 - Fipronil 0.3 GR, T7 - Chlorantraniliprole 0.4 GR, and T8 - Cartap hydrochloride 4% GR. Additionally, combination treatments included T9 (Thiamethoxam 25% WG + Fipronil 0.3 GR), T10 (Thiamethoxam 25% WG + Chlorantraniliprole 0.4 GR), T11 (Thiamethoxam 25% WG + Cartap hydrochloride 4% GR), T12 (Carbofuran 3% CG + Chlorantraniliprole 0.4 GR), T13 (Carbofuran 3% CG + Cartap hydrochloride 4% GR), and a control (T14 - water spray). In recent years, delayed transplanting has led to an increasing incidence of gall midge in specific regions of Andhra Pradesh, highlighting the need to assess the effectiveness of new granular insecticides for its management. Over four consecutive seasons, the study showed that all treatments performed significantly better than the untreated control. The most effective approach for gall midge management was seed treatment with Thiamethoxam 25% WG, followed by the application of Fipronil 0.3 GR in the main field. For stem borer control, all treatments were notably superior to the control, with the best results observed from Carbofuran 3% CG applied in the nursery, followed by Chlorantraniliprole 0.4 GR in the main field. Overall, all treatments resulted in reduced leaf damage, fewer white ears before harvest, lower incidences of Brown Planthopper (BPH) and Whitebacked Planthopper (WBPH), and increased grain yield, demonstrating significant superiority over the control.